When To Use the DM DNA Test

Posted on Jul 12, 2011 in Blog, DNA Testing

Two things happened last week that made me want to write this post, first of all I received Wrangler’s histopathology report and DM test from Dr Coates.  For those of us, me included, that don’t really know what that means;

“Histopathology is the examination of tissues from the body under a microscope to spot the signs and characteristics of disease. A histopathology report describes the tissue that has been sent for examination and what its features are under the microscope. Occasionally a histopathology report is also called a biopsy report.”

Basically it’s the report that you receive back from Dr Coates when you donate your dog’s spine to research.  The report confirmed findings that are consistent with DM.  This is what you can expect if you ever receive a report like this.

“6 Jul 11: Examined are cross sections of thoracic spinal cord. The LFB/PAS stain is uniformly rather pale, with poor staining of the white matter. PAS positive granules are present in the neuronal cell bodies and small glycosaminoglycan bodies are present. GFAP staining is also fairly diffusely homogeneous, possibly increased mildly. Neurofilament stains indicate small axons throughout the cord, without much distinction regarding site. There is increased unstained space between the axons throughout the cord. Mild positive staining is seen in some cell bodies.This patient could have had DM in an advanced state, but the distribution is much greater than previously observed. Some nerve roots also have increased space between axons. SOD1 should probably be done if the dog is genotype positive.”

I really don’t know what a lot of this means, other than it confirms that Wrangler was most likely in the advanced stages of DM.  This got me thinking again that throughout all my time with Wrangler and battling the symptoms of DM, I never did actually get any kind of confirmation that Wrangler truly had DM.  In the beginning I took Wrangler to the vet a few times when he just started limping only to be told it was arthritis or possibly a few other things, before doing all the research myself, going back to the vet and then having the vet agree that it did sound a lot like DM.  I guess I now have official confirmation that it was DM.

The second thought that made me want to write this post is every Saturday you can go to the Eddies Wheels facebook page and click on their Livestream link to watch live as customers bring their dogs in to be fitted for new carts.  I was watching this last Saturday and the first person that came in brought their dog with them.  He was a happy little guy dragging one leg, he could still pull himself around with ease, sometimes standing on both legs but he fell quite often.  I could hear the owners say, “we dont’ really know if it’s DM but he has all the symptoms” and something else about how their vet said they could do an MRI but that would be very expensive and in the end, the treatment would be the same.  Since the dog wasn’t in any real pain, he just needed a cart to assist him.

This is exactly how it started with Wrangler and most likely how it starts for many other dog owners.  Except, there is now a DNA test that you or your vet can very easily use to confirm if your dog has the gene that leads to DM.  Just because your dog has the gene doesn’t mean they will display any symptoms, however, if your dog is already showing symptoms and the test comes back positive, then this is a great way to confirm your initial suspicions of DM.

I’ve mentioned the DNA test a few times before but I mentioned it more for breeders to use before breeding any of their dogs to try and avoid passing the gene on to their puppies.  However, this may not have been the best advice for me to pass along as your dog can actually have the DM gene and not ever develop any symptoms.  On the other hand, I think this test is extremely valuable for dog owners who believe their dogs may have DM but they are in the very early stages and aren’t really sure.  Now rather than frantically reading as much as possible on the internet and eventually diagnosing your dog yourself as I did with Wrangler, you can instead have your vet order the DNA test and find out for sure in the beginning.  In the end it may not change your approach to caring for your dog but I know I would have felt a lot better knowing for sure, in the early stages, that it was DM I was dealing with.